What is ORF?

Image Format Description

ORF is the acronym and file extension for Olympus
Raw Format, the proprietary raw image file used by Olympus digital cameras. Raw image files are unprocessed data from the image sensor of a digital camera, much like film negatives of traditional photography. Each digital camera has its own proprietary raw image file, and ORF is the raw image file for the Olympus digital cameras. (Canon has CRW format, Nikon has NEF format.)

The ORF file has two types of formats, each marked by a unique magic number in the header of the file. One is magic=0x5352="RS" – this format has the primary image data in 12 bit “packed” CFA; the other is magic=0x4f52="RO" – this one contains the primary data in 12 bit “unpacked” CFA. The data in both the format types is uncompressed and both are based on TIFF IFD.

In addition to the image data, the ORF file also contains text information about the image and the conditions when the picture was taken. After the image is saved on a computer, its settings such as exposure and white balance can be edited using Olympus Master or Olympus Studio software.

The programs that can open ORF files are Adobe Photoshop CS and ORF Suite on Microsoft Windows, and Adobe Photoshop CS and Apple Aperture on Apple Mac OS. To convert OFR files to other image formats (TIFF, JPEG, GIF, BMP, etc.) use Factory Image Converter.